Edited by Lindsay W. MacDonald, Carole P. Biggam and Galina V. Paramei
[Not in series 217] 2018
► pp. 319–339
Coloured filters have been used, controversially, to reduce the perceptual distortions and discomfort sometimes associated with difficulty reading. It has been claimed that the filters can improve reading fluency. A neurological theory of visual stress is offered that attempts to examine perceptual distortions of text and the discomfort it evokes in relation to the way in the visual system evolved to process natural images. There are many possible interactions between colour and spatial processing, some involving the temporal modulation of electric lighting, and others the close relationship between colour contrast and the cortical haemodynamic response. It is argued that coloured filters can sometimes reduce the effects of strong visual stimulation when the visual cortex is hyperexcitable.